To accurately align a back lid in the direction from six o'clock to twelve o'clock of a watch.

This device for fixing the back lid 6 having a screw thread 8 on the circumference to an intermediate member 28 of a watch case 26 is equipped with an intervening part 1 having an elastic blocking member 4 and a metal part 2 concentric with the elastic blocking member 4 and pushed into a lower part of the intermediate member 28 of the watch 26. The back lid 6 is screwed onto the metal part 2. When the back lid 6 is completely screwed onto the metal part 2, the metal part 2 can be slid rotatably on the elastic blocking member 4 up to a stop point. The elastic blocking member 4 can be slid rotatably from the stop point on the intermediate member 28 of the watch 26. Hereby, alignment of the back lid 6 to the vertical axis passing twelve o'clock to six o'clock of the watch 26 can be adjusted.