To provide a medical instrument which makes a portable instrument easily connectable to an installed instrument.

An insertion support apparatus which is the medical instrument comprises: an instrument 3 installed in a medical office and an installed instrument 5 for inspection which are first medical instruments having at least one or more pieces of peripheral equipment for medical use and connection means; a support apparatus body 1 which is a second medical instrument having a prescribed processing function and freely attachably and detachably connectable to the instrument 3 and the installed instrument 5; a connector part 31 which is a first connector part provided on the instrument 3 or the installed instrument 5; a connector part 25 which is a second connector part connectable to the connector part 31 and provided to the support apparatus body 1 so as to be positioned relatively to the connector part 31; and a slide mechanism 110 for sliding the connector part 25 to a rear panel 101 which is the exterior member of the support apparatus body 1 when the connector part 31 and the connector part 25 are fit.