To simply and surely fix or release the fixing base and the base of a bed to or from each other.

The bed is constituted so that a body receiving base for receiving a user's body is disposed at the upper part of the base, the base is disposed detachably at the upper part of the fixing base, a connection boss is formed at the fixing base, an upper fitting piece to fit in the upper part of the connection boss is formed at the base, and a lower fitting piece to be fitted in the lower part of the connection boss is provided swingably at the base, so that while the lower fitting piece is fitted into the lower part of the connection boss, the lower fitting piece can be fixed to the base. Moreover, vertically moving arms for vertically moving the base are swingably arranged, a cylindrical connection boss is formed at the arms, and the upper fitting piece and the lower fitting piece are formed in the shape of a circular arc along the outer peripheral surface of the connection boss, thereby the connection boss is turnably connected to the upper fitting piece and the lower fitting piece.