The present invention provides a method of manufacturing a microdevice having a fine capillary cavity formed as a cut portion of a very thin layer which is likely to be broken, particularly a method of manufacturing a microdevice having complicated passages formed in three dimensions with high productivity. Also, the present invention provides a multi-functional microdevice which has a fine capillary passage formed by laminating plural resin layers, fine capillary cavities piercing through the respective layers to communicate and intersect three-dimensionally with each other, a space which should serve as a reaction chamber, a diaphragm valve, and a stopper structure. The method includes the steps of forming a semi-cured coating film having a cut portion made of an active energy ray curable composition on a coating substrate, laminating the semi-cured coating film with another member and removing the substrate, irradiating the semi-cured coating film again with an active energy ray before and/or after the removal of the substrate, thereby curing the coating film and bonding with said another member. The microdevice has a multi-layered structure wherein a member (J') {selected from a member having a cut portion piercing through the member, a member having a recessed cut portion on the surface, and a member having a cut portion piercing through the member and a recessed cut portion on the surface}, a member (K') and one or more active energy ray curable resin layers (X') having a cut portion at a portion of the layer, the cut portion having a minimum width within a range from 1 to 1000 .mu.m, are laminated and two or more cut portions in the members are connected to form a cavity.