The present invention provides a marker unit which can be easily installed in the same target object under the same condition, for example. The marker unit of the present invention includes: an upper substrate; and a lower substrate, wherein the upper substrate is laminated on the lower substrate to form a laminate, the lower substrate has a lower substrate detection target portion exposed to an upper surface side of the laminate on an upper surface thereof, the lower substrate has a positioning portion on a lower surface thereof, the detection target portion is detectable from an upper surface side of the laminate, and the positioning portion has a shape that determines a position with respect to an installation target portion of an installation target object in which the marker unit is to be installed.