A bed is composed of combining a wheelchair and a bed main body portion. The wheelchair has a seating bottom portion composed of bendably coupling a plurality of divided members, a chair bottom support member supporting the seating bottom portion, a chair base portion for fixing the chair bottom support member, and traveling wheels supporting the chair base portion. The bed main body portion has a bed bottom portion composed of bendably coupling a plurality of divided members, a bed bottom support member supporting the bed bottom portion, and a bed base portion for fixing this bed bottom support member. In the case where the wheelchair and the bed main body portion are combined, a support member supporting the seating bottom portion is switched from the chair bottom support member to the bed bottom support member, and the bed bottom portion and the seating bottom portion integrally perform posture change in accordance with posture change of the bed bottom support member.