diff --git a/ROADMAP.md b/ROADMAP.md
index 56e9541..5b7e853 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -20,7 +20,7 @@
 
 -	[x] Терраформация, 0 - 100%
 -	[x] Кристаллы (базовый ресурс)
--	[ ] Кислород
+-	[x] Кислород
 -	[ ] Минералы
 -	[ ] Металлы
 
diff --git a/src/app.cr b/src/app.cr
index 702691d..aed5bda 100644
--- a/src/app.cr
+++ b/src/app.cr
@@ -131,8 +131,9 @@ class App
   end
 
   def render_resources(world)
-    printf "Resources:\n  Crystals:       %5d\n  Terraformation: %5d\n",
+    printf "Resources:\n  Crystals:       %5d\n  Oxygen:         %5d\n  Terraformation: %5d\n",
       world.resources[Game::Resource::Type::Crystals],
+      world.resources[Game::Resource::Type::Oxygen],
       world.resources[Game::Resource::Type::Terraformation]
   end
 
diff --git a/src/game/building.cr b/src/game/building.cr
index 66f9902..ff5a371 100644
--- a/src/game/building.cr
+++ b/src/game/building.cr
@@ -9,12 +9,13 @@ module Game
   end
 
   class Mining
-    def initialize(@ts : TimeSpan, @resource : Resource, @input : ResourceBag)
+    def initialize(@ts : TimeSpan, @resource : Resource, @input : ResourceBag, @deposit : Bool = true)
     end
 
     getter ts
     getter resource
     getter input
+    getter deposit
   end
 
   class Construction
@@ -47,6 +48,7 @@ module Game
       StartPoint
       CrystalMiner
       CrystalRestorer
+      OxygenCollector
       Terraformer
     end
 
diff --git a/src/game/building_factory.cr b/src/game/building_factory.cr
index 5eeed31..b4fc0a2 100644
--- a/src/game/building_factory.cr
+++ b/src/game/building_factory.cr
@@ -45,6 +45,23 @@ module Game
         }
       )
 
+      add(
+        Building.new Building::Type::OxygenCollector, **{
+          shortcut:     "oxygen",
+          construction: Construction.new(
+            ts: 60,
+            cost: ResourceBag.new({Resource::Type::Crystals => 200}),
+            requirements: [] of Game::Building::Type
+          ),
+          mining: Mining.new(
+            ts: 30,
+            resource: Resource.new(Resource::Type::Oxygen, 10),
+            input: ResourceBag.new({Resource::Type::Crystals => 5}),
+            deposit: false
+          ),
+        }
+      )
+
       add(
         Building.new Building::Type::Terraformer, **{
           shortcut:     "terr",
@@ -59,6 +76,7 @@ module Game
             ts: 60,
             input: ResourceBag.new({
               Resource::Type::Crystals => 50,
+              Resource::Type::Oxygen   => 20,
             }),
             output: ResourceBag.new({
               Resource::Type::Terraformation => 5,
diff --git a/src/game/command.cr b/src/game/command.cr
index fef0ec0..5084561 100644
--- a/src/game/command.cr
+++ b/src/game/command.cr
@@ -74,6 +74,15 @@ module Game
       if !world.resources.has(mining.input)
         return mining.ts
       end
+      need_deposit = mining.deposit
+      if need_deposit
+        calc_for_deposit world, mining
+      else
+        calc_for_non_deposit world, mining
+      end
+    end
+
+    private def calc_for_deposit(world : World, mining : Mining) : TimeSpan
       resource = mining.resource
       deposit_tile = nearest_deposit(world, resource.type)
       stock_tile = nearest_stock(world)
@@ -81,8 +90,18 @@ module Game
         mined_amount = deposit_tile.dep.dec(resource.amount)
         @holded = resource.type.to_res mined_amount
         mining.ts +
-          2 * tile.point.distance(stock_tile.point) +
-          2 * tile.point.distance(deposit_tile.point)
+          2 * @point.distance(stock_tile.point) +
+          2 * @point.distance(deposit_tile.point)
+      else
+        mining.ts
+      end
+    end
+
+    private def calc_for_non_deposit(world : World, mining : Mining) : TimeSpan
+      stock_tile = nearest_stock(world)
+      if stock_tile
+        @holded = mining.resource
+        mining.ts + 2 * @point.distance(stock_tile.point)
       else
         mining.ts
       end
diff --git a/src/game/resources.cr b/src/game/resources.cr
index 67c1db1..89e190d 100644
--- a/src/game/resources.cr
+++ b/src/game/resources.cr
@@ -3,6 +3,7 @@ require "./types"
 struct Game::Resource
   enum Type
     Crystals
+    Oxygen
     Terraformation
 
     def to_res(amount : Capacity)