Abstract: The present invention provides a novel method capable of easily and rapidly inspecting the susceptibility of bacteria or fungi to an antimicrobial drug and an inspection system for use in the method. The inspection method of the present invention is a method for inspecting susceptibility of bacteria or fungi to an antimicrobial drug using a micro-device having a flow channel, including: an incubating step of incubating a mixture of the antimicrobial drug and a bacterial suspension to be inspected in the flow channel of the micro-device; and a detecting step of detecting bacteria or fungi derived from the bacterial suspension to be inspected in an observation area of the flow channel of the micro-device. The detecting step can be performed by detecting an increase or decrease in the number of or a change in shape of bacteria or fungi derived from the bacterial suspension to be inspected in the observation area by a microscope or the like.