A magnetic recording and reproduction apparatus includes a main chassis having a rotatable head cylinder provided thereon; and a sub chassis on which a tape cassette is mountable. The sub chassis is movable with respect to the main chassis between a tape cassette mountable position and a tape pull-out completion position, and the tape cassette mountable position is a position at which the tape cassette is mountable on the sub chassis and the tape pull-out completion position is a position at which information recording to and information reproduction from the tape, which has been pulled out from the tape cassette and has been wound around the rotatable head cylinder, can be performed. A portion of the main chassis along a forward end thereof is cut out toward the rotatable head cylinder.