PROBLEM TO BE SOLVED : To provide a novel substituted 6, 7-dihydro-5H-benzo[7]annulene compound having inhibitory action and decomposition action of an estrogen receptor. SOLUTION : A 6, 7-dihydro-5H-benzo[7]annulene derivative has a [4-[(3S)-1-(3-fluoroalkyl)pyrrolidine-3-yl]oxyphenyl] group at the 5-position and has a phenyl group or a heteroaryl group at the 6-position. A preparation method of the 6, 7-dihydro-5H-benzo[7]annulene derivative and a therapeutic use for cancer are provided. SELECTED DRAWING : None COPYRIGHT : (C)2019, JPO&INPIT