A distributed constant filter includes a resonator that is not grounded and a first ground electrode. The first ground electrode faces the resonator in a first direction (Z). The resonator is a distributed constant line resonator. The resonator includes a plurality of distributed constant lines and a via conductor. The plurality of distributed constant lines are arranged in layers in the first direction (Z). The via conductor extends in the first direction (Z). Each of the plurality of distributed constant lines is connected to the via conductor only at one end portion of both end portions of the distributed constant line.