A monolithic multijunction solar cell having exactly four subcells, an uppermost first subcell having a layer made up of a component having the elements AlInP, and the lattice constant a1 of the layer being between 0.572 nm and 0.577 nm, and the indium content being between 64% and 75%, and the Al content being between 18% and 32%, and the third subcell having a layer made up of a compound having at least the elements GaInAs, and the lattice constant of the layer being between 0.572 and 0.577, and the indium content of the layer being greater than 17%, and the second subcell comprising a layer including a compound which has at least the elements GaInAsP, the layer having an arsenic content between 22% and 33% and an indium content between 52% and 65%. and the lattice constant a2 being between 0.572 and 0.577.