According to the present invention, there is provided a method for detecting a bonding failure part of a compound semiconductor chip cut from a compound semiconductor wafer in which a first transparent substrate composed of a compound semiconductor having a light-emitting layer is bonded with a second transparent substrate composed of a compound semiconductor, including irradiating the compound semiconductor chip with a coaxial vertical light, and identifying a color of a reflected-light from the bonding failure part of the compound semiconductor chip to detect the bonding failure part. As a result, it is possible, to provide a method for detecting a bonding failure part which can precisely detect a bonding failure part on a bonding interface of a compound semiconductor chip cut from a compound semiconductor wafer in which two transparent substrates composed of a compound semiconductor are directly bonded with each other.