An assisting tool assists a pull-out operation of a cassette configured to be able to advance and retreat in relation to a housing between an accommodated position where the cassette is accommodated in the housing and a pulled-out position where the cassette is pulled out from the housing, and the cassette is formed with a handhold part recessed in a push-in direction opposite to a pull-out direction from a surface intersecting the pull-out direction, and the assisting tool includes a rod part, and a hook part provided at the rod part and engageable with the handhold part.