driving rotating member 30 which rotates accordingly the door 20 can be automatically opened or closed by the user 39 s one touch operation the driving rotating member 30 includes a motor 31 a rotating shaft 32 coupled to the motor 31 as one body and a rotary member 33 which is connected to the rotary shaft 32 and has a rotating center centered on the rotating shaft 32 and rotates the motor 31 is preferably embodied as a geared d c motor that rotates bidirectionally at a slow speed and with high torque the rotary member 33 consists of a rotary plate 34 formed in a wedge shape and having first and second bosses 35 and 36 that protrude normally from corners of the front of the rotary plate 34 a one touch button for driving the motor 31 can be positioned on a control panel not shown mounted on the top of the main body 10 so the user can easily manipulate the one touch button however as shown in fig2 a one touch button 70 is embodied as a foot switch arranged at a lower part of the front side of the main body 10 so a user can manipulate the one touch button 70 with a foot a door open sensor 50 and a door closed sensor 60 which are used to stop a driving of the motor 31 in order to stop the door opening operation and the door closing operation are respectively mounted to a rear part and a front part of the door that is when the door closing operation is terminated the motor 31 stops driving in response to a signal from the door closed sensor 60 when the door opening operation is terminated the motor 31.