Provided is a solid electrolyte material comprising Li, Y, Br, and Cl wherein in an X-ray diffraction pattern in which Cu-Kα is used as a radiation source, peaks are present within all ranges of diffraction angles 2θ of 15.1° to 15.8°, 27.3° to 29.5°, 30.1° to 31.1°, 32.0° to 33.7°, 39.0° to 40.6°, and 47.0° to 48.5°.