A vehicle casing comprising: a metal frame (10; 40); and a resin cover (20; 50) that covers the metal frame (10; 40), and the resin cover (20; 50) accommodating vehicle components inside the metal frame (10; 40), wherein the metal frame (10; 40) includes a bearing supporting boss portion (13, 16; 43) that rotatably supports, inside the resin cover (20; 50), a shaft member (31; 71) that is one of the vehicle components and rotates about a shaft center, and a mount boss portion (14; 44) that is for fixing the vehicle casing to a vehicle body,the bearing supporting boss portion (13, 16; 43) is disposed at a position separate from an inner surface of the resin cover (20; 50), and the resin cover (20; 50) is disposed to cover the entire metal frame (10; 40) except a portion provided with the mount boss portion (14; 44), and characterized by an arm portion (12; 42) connected to the bearing supporting boss portion (13, 16; 43), the arm portion (12; 42) being separated from an inner surface of the resin cover (20; 50), and the arm portion (12; 42) extending from a flange portion of the metal frame (10; 40) to the bearing supporting boss portion (13, 16; 43). a metal frame (10; 40); and a resin cover (20; 50) that covers the metal frame (10; 40), and the resin cover (20; 50) accommodating vehicle components inside the metal frame (10; 40), wherein the metal frame (10; 40) includes a bearing supporting boss portion (13, 16; 43) that rotatably supports, inside the resin cover (20; 50), a shaft member (31; 71) that is one of the vehicle components and rotates about a shaft center, and a mount boss portion (14; 44) that is for fixing the vehicle casing to a vehicle body,the bearing supporting boss portion (13, 16; 43) is disposed at a position separate from an inner surface of the resin cover (20; 50), and the resin cover (20; 50) is disposed to cover the entire metal frame (10; 40) except a portion provided with the mount boss portion (14; 44), and characterized by an arm portion (12; 42) connected to the bearing supporting boss portion (13, 16; 43), the arm portion (12; 42) being separated from an inner surface of the resin cover (20; 50), and the arm portion (12; 42) extending from a flange portion of the metal frame (10; 40) to the bearing supporting boss portion (13, 16; 43). a bearing supporting boss portion (13, 16; 43) that rotatably supports, inside the resin cover (20; 50), a shaft member (31; 71) that is one of the vehicle components and rotates about a shaft center, and a mount boss portion (14; 44) that is for fixing the vehicle casing to a vehicle body,the bearing supporting boss portion (13, 16; 43) is disposed at a position separate from an inner surface of the resin cover (20; 50), and the resin cover (20; 50) is disposed to cover the entire metal frame (10; 40) except a portion provided with the mount boss portion (14; 44), and characterized by an arm portion (12; 42) connected to the bearing supporting boss portion (13, 16; 43), the arm portion (12; 42) being separated from an inner surface of the resin cover (20; 50), and the arm portion (12; 42) extending from a flange portion of the metal frame (10; 40) to the bearing supporting boss portion (13, 16; 43).