A filter circuit includes an input terminal configured to input an input signal; first to ith blocks which have first to ith resonators as transmission lines having first to ith resonance frequencies; a power divider configured to distribute the input signal to the first to ith blocks; a power combiner configured to combine signals which have passed through the first to ith blocks to obtain a combined signal; and an output terminal configured to output the combined signal, wherein a jth block includes a phase adjustment unit which provides a signal of the jth block with a phase difference within a range of {(180±30)+(360×n)} degrees from a signal of a (j+1)th block, and a resonator having a large amount of group delay has a greater line width than a resonator having a small amount of group delay.