To provide an apparatus for manufacturing a membrane electrode assembly which suppresses slack in a sub-gasket film added to both sides of the membrane electrode assembly.SOLUTION: A sub-gasket adding device attaches a second sub-gasket film 92b to the other side of a membrane electrode assembly 85 in which a first sub-gasket 92a is added to one side thereof. The sub-gasket adding device includes a position specifying section 410 for specifying the position of a second catalyst layer 84 on a first base material B1, a third half cut section for providing the second sub-gasket film 92b with a cutting portion C9b through which a corresponding area A93 having a shape corresponding to the second catalyst layer 84 and a non-corresponding area other than the corresponding area A93 are separated according to the position of the second catalyst layer 84 which is specified by the position specifying section 410, a second attaching mechanism 3 for attaching the second sub-gasket film 92b to the other side of the first base material B1 while aligning the position of the corresponding area A93 with the position of the second catalyst layer 84.SELECTED DRAWING: Figure 22