An exposure apparatus having an illumination optical system for illuminating a mask (R 1, R 2) with illumination light and a projection optical system for projecting a pattern image of the illuminated mask onto a substrate, the apparatus comprising: a body having a frame member and a first base member, the frame member being arranged to support the projection optical system and itself being supported via a first vibration isolation mechanism, and the first base member being placed above the projection optical system and having an opening through which the illumination light passes; a first stage system having a first movable body and a first motor, the first movable body being placed on the first base member and being arranged to hold the mask, and the first motor being configured to drive the first movable body; a first encoder system having a plurality of first heads (26A 1, 26A 2, 26A 3, 26B 1, 26B 2, 26B 3, 26C 1, 26C 2, 26C 3) and configured to measure positional information of the first movable body, each of the plurality of first heads being arranged to irradiate a first measurement beam to a first grating section (24A, 24B, 28) that has a reflection type grating and is placed substantially parallel to a predetermined plane orthogonal to an optical axis of the projection optical system; a second base member placed below the projection optical system and supported via a second vibration isolation mechanism that is different from the first vibration isolation mechanism; a second stage system having a plurality of second movable bodies and a second motor, the plurality of second movable bodies being placed on the second base member and being each arranged to hold a substrate, and the second motor being configured to drive the plurality of second movable bodies; a second encoder system having a plurality of second heads (46A, 46B, 46C, 46D) and configured to measure positional information of the second movable body, each of the plurality of second heads being arranged to irradiate a second measurement beam to a second grating section (44A, 44B, 44C, 44D) that has a reflection type grating and is placed substantially parallel to the predetermined plane; and a control system configured to control the first motor based on measurement information of the first encoder system and also to control the second motor based on measurement information of the second encoder system so that scanning exposure of the substrate, in which the mask and the substrate are each moved relative to the illumination light, is performed, wherein the plurality of first heads include at least one first head that is switched from one of a state and another state to the other due to movement of the first movable body in a first direction within the predetermined plane, in the state the first measurement beam being irradiated on the reflection type grating, and in the another state the first measurement beam moving off from the reflection type grating. a body having a frame member and a first base member, the frame member being arranged to support the projection optical system and itself being supported via a first vibration isolation mechanism, and the first base member being placed above the projection optical system and having an opening through which the illumination light passes; a first stage system having a first movable body and a first motor, the first movable body being placed on the first base member and being arranged to hold the mask, and the first motor being configured to drive the first movable body; a first encoder system having a plurality of first heads (26A 1, 26A 2, 26A 3, 26B 1, 26B 2, 26B 3, 26C 1, 26C 2, 26C 3) and configured to measure positional information of the first movable body, each of the plurality of first heads being arranged to irradiate a first measurement beam to a first grating section (24A, 24B, 28) that has a reflection type grating and is placed substantially parallel to a predetermined plane orthogonal to an optical axis of the projection optical system; a second base member placed below the projection optical system and supported via a second vibration isolation mechanism that is different from the first vibration isolation mechanism; a second stage system having a plurality of second movable bodies and a second motor, the plurality of second movable bodies being placed on the second base member and being each arranged to hold a substrate, and the second motor being configured to drive the plurality of second movable bodies; a second encoder system having a plurality of second heads (46A, 46B, 46C, 46D) and configured to measure positional information of the second movable body, each of the plurality of second heads being arranged to irradiate a second measurement beam to a second grating section (44A, 44B, 44C, 44D) that has a reflection type grating and is placed substantially parallel to the predetermined plane; and a control system configured to control the first motor based on measurement information of the first encoder system and also to control the second motor based on measurement information of the second encoder system so that scanning exposure of the substrate, in which the mask and the substrate are each moved relative to the illumination light, is performed, wherein the plurality of first heads include at least one first head that is switched from one of a state and another state to the other due to movement of the first movable body in a first direction within the predetermined plane, in the state the first measurement beam being irradiated on the reflection type grating, and in the another state the first measurement beam moving off from the reflection type grating.