To provide a navigation device and a navigation program which enable a user to easily specify a passing area and search for a travel route passing the specified area with little processing load.

A user specifies a start point S and a goal point G, and also specifies a passing area A on a map displayed on a screen. The device efficiently performs a route search by determining start side boundary points s1 to s3 and goal side boundary points g1 to g4 among all boundary points of the specified passing area A, and performing total 19 times of route search which includes three routes from the start point S to the respective start side boundary points s1 to s3, 12 routes from the respective start side boundary points s1 to s3 to the respective goal side boundary points g1 to g4, and 4 routes from the respective goal side boundary points g1 to g4 to the goal point G. Then, the device determines a combination of respective travel routes, the combination having the lowest total cost among all combinations of the respective travel routes, as a travel route which leads the user from the start point S to the goal point G by passing the passing area A.