direction in fig2 side regulation plates 1 and 2 control the widthwise position of the sheets s stored in each of the cassettes 100 and can be displaced in the widthwise direction in accordance with the width of the sheets s a rear end regulation plate 3 controls the position of the sheets s at the rear in the sheet conveying direction and can be displaced in the sheet conveying direction in accordance with the length of the sheets s the cassette 100 can be pulled along rails 19 and 20 in fig3 when a user sets up the cassette 100 he or she need only pull the cassette 100 out from the front of the printer main body 1001 as is shown in fig2 a protrusion 100 a is formed for each cassette 100 when the cassette 100 is stored in the cassette storage portion 1005 the protrusion 100 a is detected by a cassette attachment and detachment detection sensor 17 that is provided for the cassette storage portion 1005 a detection signal obtained by the cassette attachment and detachment detection sensor 17 is transmitted to the controller 120 which employs the received detection signal to determine whether the cassette 100 is attached to the cassette storage portion 1005 or has been pulled out in each of the cassettes 100 as is shown in fig3 a lifter support 16 is provided as elevatable sheet stacking means used to mount the sheets s as the cassette 100 is inserted or removed the lifter support 16 is elevated or lowered by a lifter motor 18 in fig4 for example when a user.