A switch apparatus includes: a first switch circuit for receiving data from external, sending first data including the received data, and sending second data including the received data after a predetermined time period from sending of the first data; a first controller for outputting the first data received from the first switch circuit; a second controller for outputting the second data received from the first switch circuit; and a second switch circuit for receiving the first data from the first controller and second data received from the second controller, sending the first data to external when the first data is free from an error, and sending the second data to external when the first data has an error and when the second data is free from an error.