Acoustic wave filter, acoustic wave device, multiplexer, and communication apparatus

An acoustic wave filter, comprising:

• a piezoelectric substrate,
• a serial arm comprising one or more serial resonance portions on the piezoelectric substrate, and
• one or more parallel resonance portions on the piezoelectric substrate, configuring a ladder-type filter together with the serial arm, wherein:
• a first resonance portion which is any one among the one or more serial resonance portions and the one or more parallel resonance portions comprises
• a first resonator comprising an IDT electrode on the piezoelectric substrate and a pair of reflectors on the two sides of the IDT electrode and
• a first capacity portion connected in parallel with the first resonator,
• a capacitance of the first capacity portion is 0.8 time or more of a capacitance of the IDT electrode in the first resonator, and
• a difference between an anti-resonance frequency and a resonance frequency of the first resonance portion is smaller than a difference between an anti-resonance frequency and a resonance frequency of the first resonator.