Map processing device and map processing method

A problem to be solved by the present invention is that a host vehicle position calculated on the basis of a GNSS is affected by shielding, reflection, diffraction, and the like of a positioning radio wave due to a structure, depending on a structure environment present around a receiver and an arrangement of positioning satellites at the date and time, and a detected measured position is output in a biased manner. A map processing device of the present invention processes map information used for positioning a host vehicle, and includes: a satellite orbit information acquisition unit that acquires position information of a plurality of positioning satellites; a pseudo distance acquisition unit that calculates a pseudo distance from the plurality of positioning satellites based on positioning radio waves respectively received from the plurality of positioning satellites; a positioning available satellite verification unit that identifies, among the plurality of positioning satellites, a positioning satellite for which a distance to the host vehicle position and the pseudo distance do not match as a positioning unavailable satellite; and a map generation unit that generates a map in which a direction from the host vehicle position to the positioning unavailable satellite is stored in association with the host vehicle position as a shielded range in which a positioning radio wave from the positioning unavailable satellite is shielded.