A cooking appliance having an automatic opening door, the cooking appliance comprising: a main body that is provided with a cooking chamber therein; a door that is configured to open and to close an open front of the cooking chamber; a latch; and a latch holder that is configured to catch the latch to keep the door closed or to release the latch to open the door; wherein the cooking appliance further comprises a lever that is configured to release the latch from the latch holder when the latch is caught in the latch holder; an opening sensing switch that is configured to be switched on or switched off, respectively, in a state where the latch is caught in the latch holder and in a state where the latch is released from the latch holder; a driving device that is configured to operate the lever, wherein the driving device comprises a pusher that is configured to push the lever and a motor that is configured to drive the pusher; a return/stop switch that is configured to be switched on or switched off, respectively, in a state where the driving device is in a predetermined position and in a state where the driving device moves out of the predetermined position; and a controller that is configured to control an operation of an automatic opening of the door; wherein power supplied to the driving device is supplied to the motor, and the return/stop switch is configured to be switched on or switched off based on a position of the pusher; wherein the controller is configured to control the driving device depending on the state of the opening sensing switch and the return/stop switch, characterised in that the controller is configured to generate a first error signal of a problem with the operation of the latch when the opening sensing switch is kept on after a predetermined period of time after electric power is supplied to the motor with an instruction to open the door input by the user, and the return/stop switch is turned off; wherein the controller is configured to generate a second error signal of a problem with the return/ stop switch when the return/stop switch is not turned on after the predetermined period of time while the opening sensing switch is turned off after normal operation of motor with an instruction to open the door input by the user; wherein the controller is configured to generate a third error signal of a problem with the motor when the opening sensing switch is kept on after a predetermined period of time after electric power was supplied to the motor; wherein the controller is configured to generate a fourth error signal of a problem with the motor or the return/stop switch when the opening sensing switch is kept off after electric power was supplied to the motor; and wherein the controller is configured to control the driving device depending on the generated error signals. wherein the cooking appliance further comprises a lever that is configured to release the latch from the latch holder when the latch is caught in the latch holder; an opening sensing switch that is configured to be switched on or switched off, respectively, in a state where the latch is caught in the latch holder and in a state where the latch is released from the latch holder; a driving device that is configured to operate the lever, wherein the driving device comprises a pusher that is configured to push the lever and a motor that is configured to drive the pusher; a return/stop switch that is configured to be switched on or switched off, respectively, in a state where the driving device is in a predetermined position and in a state where the driving device moves out of the predetermined position; and a controller that is configured to control an operation of an automatic opening of the door; wherein power supplied to the driving device is supplied to the motor, and the return/stop switch is configured to be switched on or switched off based on a position of the pusher; wherein the controller is configured to control the driving device depending on the state of the opening sensing switch and the return/stop switch, characterised in that the controller is configured to generate a first error signal of a problem with the operation of the latch when the opening sensing switch is kept on after a predetermined period of time after electric power is supplied to the motor with an instruction to open the door input by the user, and the return/stop switch is turned off; wherein the controller is configured to generate a second error signal of a problem with the return/ stop switch when the return/stop switch is not turned on after the predetermined period of time while the opening sensing switch is turned off after normal operation of motor with an instruction to open the door input by the user; wherein the controller is configured to generate a third error signal of a problem with the motor when the opening sensing switch is kept on after a predetermined period of time after electric power was supplied to the motor; wherein the controller is configured to generate a fourth error signal of a problem with the motor or the return/stop switch when the opening sensing switch is kept off after electric power was supplied to the motor; and wherein the controller is configured to control the driving device depending on the generated error signals.