Resonator, filter, communication apparatus

A resonator comprising:

• a multilayer substrate including a plurality of alternately stacked dielectric layers and conductor layers, the multilayer substrate having conductor opening portions arranged in a stacking direction of the dielectric layers and the conductor layers, the conductor opening portions forming at least two inductive regions, and at least one portion where the conductor layers face each other in the stacking direction with the corresponding dielectric layers interposed therebetween, the at least one portion serving as a capacitive region and interconnecting the at least two inductive regions.