An image reading apparatus comprising: a scanner configured to read an image of a document; an operation panel configured to designate a transmission destination of scan data, the scan data including image data of the document read by the scanner; a communication interface configured to transmit the scan data to the transmission destination designated on the operation panel; and a processor configured to transmit the scan data to the transmission destination without a password in response to the transmission destination designated on the operation panel being a transmission destination of an operator who operates the operation panel, and transmit the scan data protected with a password to the transmission destination in response to the transmission destination designated on the operation panel including a transmission destination of any person other than the operator; characterized in that: the operation panel is configured to receive input of a security setting instruction for the scan data, and the processor is configured to: receive the security setting instruction via the operation panel, transmit the scan data to each transmission destination without protecting the scan data with a password in response to the security setting input to the operation panel being a first level, transmit the scan data to the transmission destination of the operator without protecting the scan data with a password and transmit the scan data protected with the password to the transmission destination of the other person other than the operator in response to the security setting input to the operation panel being a second level, and transmit the scan data protected with a plurality of passwords to each transmission destination in response to the security setting input to the operation panel being a third level. a scanner configured to read an image of a document; an operation panel configured to designate a transmission destination of scan data, the scan data including image data of the document read by the scanner; a communication interface configured to transmit the scan data to the transmission destination designated on the operation panel; and a processor configured to transmit the scan data to the transmission destination without a password in response to the transmission destination designated on the operation panel being a transmission destination of an operator who operates the operation panel, and transmit the scan data protected with a password to the transmission destination in response to the transmission destination designated on the operation panel including a transmission destination of any person other than the operator; characterized in that: the operation panel is configured to receive input of a security setting instruction for the scan data, and the processor is configured to: receive the security setting instruction via the operation panel, transmit the scan data to each transmission destination without protecting the scan data with a password in response to the security setting input to the operation panel being a first level, transmit the scan data to the transmission destination of the operator without protecting the scan data with a password and transmit the scan data protected with the password to the transmission destination of the other person other than the operator in response to the security setting input to the operation panel being a second level, and transmit the scan data protected with a plurality of passwords to each transmission destination in response to the security setting input to the operation panel being a third level. the operation panel is configured to receive input of a security setting instruction for the scan data, and the processor is configured to: receive the security setting instruction via the operation panel, transmit the scan data to each transmission destination without protecting the scan data with a password in response to the security setting input to the operation panel being a first level, transmit the scan data to the transmission destination of the operator without protecting the scan data with a password and transmit the scan data protected with the password to the transmission destination of the other person other than the operator in response to the security setting input to the operation panel being a second level, and transmit the scan data protected with a plurality of passwords to each transmission destination in response to the security setting input to the operation panel being a third level. receive the security setting instruction via the operation panel, transmit the scan data to each transmission destination without protecting the scan data with a password in response to the security setting input to the operation panel being a first level, transmit the scan data to the transmission destination of the operator without protecting the scan data with a password and transmit the scan data protected with the password to the transmission destination of the other person other than the operator in response to the security setting input to the operation panel being a second level, and transmit the scan data protected with a plurality of passwords to each transmission destination in response to the security setting input to the operation panel being a third level.