The utility model relates to an elevator, including well (1), elevator car (2), counter weight (3), guide rail (4), the practicality is high. Halfpace (L1 L3, ), with car position detecting device (7, 10). Car position detecting device (7, 10) are including detector device (7), with pair device (10). Every pair device (10) including long and thin support arm (12), mounting base (15), with first pair component (11). Every pair device (10) including being used for fixing long and thin arm section (12a) fixing device on guide rail (4, 5), fixing device includes a mounting fixture (40), the 2nd mounting fixture (50), and be used for mounting fixture (40, 50 ) fastener (42a, the 42b of not movably fastening in long and thin arm section (12a), 52a, 52b), fastener (42a, 42b, 52a, 52b) can fasten and can release.