Bed and separating method of the some

A bed, comprising:

• a first rail;
• a second rail;
• a wheelchair having a first armrest mounting unit to and from which the first rail is attachable and detachable in a first side part thereof, and a second armrest mounting unit to and from which the second rail is attachable and detachable in a second side part thereof;
• and
• a bed main body portion having a first support portion and a second support portion in a first side part and a bed rail in a second side part thereof, wherein
• the first support portion has a first bed mounting unit to and from which the first rail or the second rail is attachable and detachable, and
• the second support portion has a second bed mounting unit to and from which the first rail or the second rail is attachable and detachable.