An aid device configured to assist a transfer operation of a care receiver, the aid device comprising: a base； an arm, provided on the base in a front-rear swingable manner； a support portion, configured to support a part of the care receiver's body, provided on the arm in a front-rear swingable manner； a main body portion provided on the base in a front-rear tiltable manner； an actuator, having a movable portion, extending and contracting from the main body portion； a linking mechanism configured to transmit a first operation to the forward swing of the support portion and a second operation to the forward swing of the arm, the first operation being an operation in which the movable portion extends from a contracted position to a predetermined intermediate position, and the second operation being an operation in which the movable portion extends from the intermediate position to an extended position； and an arm restricting mechanism configured to bias the upper portion of the arm toward the movable portion.
