An X-ray CT apparatus for obtaining an internal image of a test subject by using X-rays. The X-ray CT apparatus has: an X-ray generator; an X-ray detector; a first casing for enclosing the X-ray generator and the X-ray detector; a test-subject table; a first table transporting mechanism for transporting the test-subject table between a first table position and a second table position, the first table position being a position where the main portion of the test-subject table receives X-rays from the X-ray generator, and the second table position being a position where the main portion of the test-subject table is on the outside of the first casing; and a second table transporting mechanism capable of vertically transporting the test-subject table. The first table transporting mechanism and the second table transporting mechanism operate in association with each other.