Microchannel chip and microanalysis system

A micro flow path chip comprising an assembly of a first thin plate and a second thin plate, further comprising:

• a first recessed part having an opening formed on a joint surface and a side surface of the first plate;
• and
• a second recessed part and a groove formed on a joint surface of the second plate, the second recessed part having an opening on the joint surface and a side surface of the second plate, the groove having a smaller size in a width direction and a depth direction than the second recessed part in a cross section parallel to the side surface, wherein:
• the first recessed part and the second recessed part have no undercut part such that each of the first and second recessed parts has a shape of a cross section parallel to the joint surface, the shape of the cross section being unchanged or decreasing as the cross section is away from the joint surface;
• the first plate is joined to the second plate such that the first recessed part faces the second recessed part, to form a side opening region being a recess which opens on the side surface and a flow path formed by closing the groove with the joint surface of the first plate;
• the first recessed part and the second recessed part form the side opening region;
• the side opening region is in communication with the flow path through a wider region;
• the wider region blocks ingress of an adhesive to be introduced into a gap generated when a glass tube is inserted into the side opening region, by an action of capillary repulsion;
• and
• the side opening region is a glass tube inserting port.