There is provided a portable mixing recorder which enables a user to readily produce music using overdubbing andor other recording techniques while suppressing degradation of sound quality to the minimum without excessive concern for space restriction. A network interface card is inserted into a computer terminal device. A tubular sleeve is mounted inside the housing to transmit rotary drive to a drilling bit. The vacuum chamber is disposed in the vicinity of the suction roller at an upstream position in the conveying route so as to form an S-shape in the conveying route with the outer peripheral surface of the suction roller.