An electronic device including a first microcomputer, a second microcomputer, and communication part configured to communicate with an external device is provided. The first microcomputer has a first storage configured to store a first program, and a first controller configured to execute a first process by using the first program stored in the first storage. The second microcomputer has a second storage configured to store a second program, and a second controller configured to execute a second process by using the second program stored in the second storage. The second controller of the second microcomputer acquires, from the external device, difference data for updating the first program stored in the first storage of the first microcomputer by using the communication part, and updates the first program stored in the first storage of the first microcomputer by using the acquired difference data and the second program stored in the second storage.