A microstripline filter in which characteristics of a plurality of resonators which are connected to one another in a manner of inductive coupling are precisely set. The microstripline filter includes a ground electrode, main-surface lines, common electrodes, short-circuit electrodes, and input/output electrodes. The ground electrode is arranged on a lower surface of a dielectric substrate having a rectangular plate shape. The plurality of main-surface lines are arranged on an upper surface of the dielectric substrate and form respective resonators. The common electrodes connect some of the main-surface lines to one another in conduction states. The plurality of short-circuit electrodes connect a group of the main-surface lines which are brought to conduction states by the common electrodes to the ground electrode through an identical side surface of the dielectric substrate. The input-and-output electrodes are connected to corresponding ones of the resonators including the main-surface lines.