To obtain a unidirectional surface acoustic wave converter which can make the insertion loss smaller, even when the electrode resistance is made smaller and the center frequency is made larger and improve characteristics of filters by reducing the variation in the width of electrode fingers at the time of the manufacture.

This unidirectional surface acoustic wave converter, which generates a reflected wave of an excited surface acoustic wave, is equipped repeatedly with a couple of opposite bus bars 14 and 15, a 1st electrode finger 11 which is connected to one bus bar and has a width 1/8 time as large as a wavelength λ of the surface acoustic wave, a 2nd electrode finger 12 which is connected to the other bus bar and has a gap (1/8)λ with the 1st electrode finger and a width (3/8)λ, a 3rd electrode finger 13 which is connected to the other bus bar and has a gap (1/8)λ with the 2nd electrode finger, a gap (1/8)λ with a next 1st electrode finger, and a width (1/8)λ, and a short bar 16 which partially fills the gap between the 2nd and 3rd electrode fingers.