An information recording and/or reading apparatus has a base plate, a spindle motor for rotating a disk by the output shaft perpendicular to the base plate, a rotary alignment control device for determining the rotation position of a recording/reading head of a head unit about a rotary alignment axis parallel to the output shaft of the spindle motor, a linear movement guide extending parallel to the rotary alignment axis, and a support mechanism for supporting the rotary alignment control device to be reciprocally movable along the linear movement guide. An information recording and/or reading apparatus allows very easy exchange of a recording/reading head and disk, and can avoid troubles such as damage to the recording/reading head and disk during exchange.