An exposure apparatus for exposing an object with an illumination light via a projection optical system, the apparatus comprising: a metrology frame arranged for supporting the projection optical system; a stage (WTS1, WTS2) having a holder to hold the object; a drive system having a planar motor of a magnetic levitation method to drive the stage; a measurement system having a plurality of heads (60 1, 60 ia, 60 1b, 60 2, 60 2a, 60 2b, 60 3, 60 3a, 60 3b, 60 4, 60 4a, 60 4b) and configured to measure positional information of the stage, the plurality of heads being disposed at the stage and each arranged for irradiating a scale member with a measurement beam from below the scale member, the scale member being provided at the metrology frame so that the scale member is substantially parallel to a predetermined plane orthogonal to an optical axis of the projection optical system; and a controller configured to control the drive system on the basis of the positional information, wherein the scale member has four sections (21 1, 21 2, 21 3, 21 4) that are L-shaped, in each of which a reflection-type grating is formed on a surface that the plurality of heads can face, and an opening that is surrounded by the four sections, and in the opening, an end of the projection optical system is disposed, each of the plurality of heads is configured to be capable of measuring the positional information in at least one direction of two directions (X, Y) intersecting within the predetermined plane and a direction orthogonal to the predetermined plane, the measurement system has four head groups (61 1, 61 2, 61 3, 61 4) provided at the stage so that the four head groups face the four sections, respectively, within a movement area in which the stage is moved in an exposure operation of the object, a first head group (61 1), of the four head groups, includes at least three heads that are not positioned on a same straight line, of the plurality of heads, of the at least three heads, at least two heads are configured to measure the positional information in one of the two directions so that a difference in the positional information is measured by the first head group, and the controller is configured to control the drive system so that the stage is moved while the first head group faces a first section of the four sections, and also configured to calibrate a grid error of the first section at least in a direction parallel to the predetermined plane on the basis of the difference in the positional information measured by the first head group. a metrology frame arranged for supporting the projection optical system; a stage (WTS1, WTS2) having a holder to hold the object; a drive system having a planar motor of a magnetic levitation method to drive the stage; a measurement system having a plurality of heads (60 1, 60 ia, 60 1b, 60 2, 60 2a, 60 2b, 60 3, 60 3a, 60 3b, 60 4, 60 4a, 60 4b) and configured to measure positional information of the stage, the plurality of heads being disposed at the stage and each arranged for irradiating a scale member with a measurement beam from below the scale member, the scale member being provided at the metrology frame so that the scale member is substantially parallel to a predetermined plane orthogonal to an optical axis of the projection optical system; and a controller configured to control the drive system on the basis of the positional information, wherein the scale member has four sections (21 1, 21 2, 21 3, 21 4) that are L-shaped, in each of which a reflection-type grating is formed on a surface that the plurality of heads can face, and an opening that is surrounded by the four sections, and in the opening, an end of the projection optical system is disposed, each of the plurality of heads is configured to be capable of measuring the positional information in at least one direction of two directions (X, Y) intersecting within the predetermined plane and a direction orthogonal to the predetermined plane, the measurement system has four head groups (61 1, 61 2, 61 3, 61 4) provided at the stage so that the four head groups face the four sections, respectively, within a movement area in which the stage is moved in an exposure operation of the object, a first head group (61 1), of the four head groups, includes at least three heads that are not positioned on a same straight line, of the plurality of heads, of the at least three heads, at least two heads are configured to measure the positional information in one of the two directions so that a difference in the positional information is measured by the first head group, and the controller is configured to control the drive system so that the stage is moved while the first head group faces a first section of the four sections, and also configured to calibrate a grid error of the first section at least in a direction parallel to the predetermined plane on the basis of the difference in the positional information measured by the first head group.