To provide a filter slider for a microscope which is easily manufactured and has simple constitution.

The filter slider 101 for the microscope adhered and fixed with a first optical element 103 and with a second optical element 102 at a mounting member 104, so as to face each other is provided with a vent hole 106 for making the space between the first optical element 103 and the second optical element 102 at the mounting member 104 described above, communicate with the outside.