According to the present invention, a movable wall portion (24) for forming the outer circumference of an infant accommodation space (11) can pivot forward about a portion of a region including the lower end portion and its vicinity of the movable wall portion (24) from a substantially erect position to the outside of the infant accommodation space (27). The movable wall portion (24) can move backward from a midway position in forward movement to the final backward moving position by its own weight while abrupt backward movement is suppressed by a damper (51). The present invention can provide a movable wall portion attachment mechanism (36b) of an incubator, with a relative simple arrangement, which does not produce any large sound or any large vibration when closing the movable wall portion (24), thereby avoiding that wall portions such as wall portions on the incubator base (21) side, the movable wall portion (24) or the like will be damaged.
