A controller for a life support device, the controller having a control section in charge of sequence control, the controller includes: a first interface section transmitting an output state of the control section to each part in the life support device, and transmitting an output state of each part in the life support device to the control section; and a second interface section setting an output state in response to detection of a predetermined data sequence output from the control section, and maintaining the set output state until the second interface section receives the predetermined data sequence anew. A part of the life support device is driven via the second interface section.