A hand insertion door board (36) is attached to the peripheral portion of each hand insertion window (33) formed in an outside portion of a newborn infant container (16) of an incubator (11). A holding portion (45) is formed on one side portion of the hand insertion door board (36) in the lateral direction. A bracket (52) which pivotally supports a support shaft (58) having a vertical axis is attached to the holding portion (45). A latch lever (63) is pivotally supported by the support shaft (58) of the bracket (52). A press lever (75) which releases latching operation of the latch lever (63) is pivotally attached by using the support shaft (58) of the bracket (52). When the press lever (75) is pressed against the biasing force of a compression coil spring (80), the press lever (75) presses projecting pieces (67) of the latch lever (63) to make the latch lever (63) pivot about the support shaft (58) to the release position. This arrangement provides an incubator which does not easily affect the physical condition of a newborn infant in spite of being capable of easily opening hand insertion windows by manipulation with a body part such as the elbow other than the hands, and allows to use common latch mechanisms for the hand insertion doors in different orientations.