The aim of the Verifix-Project is to investigate the construction of correct compilers. The language MIS serves as the intermediate language to be compiled into machine code of the DEC-Alpha processor. This document contains an ASM specification of the language. A MIS program is a set of basic blocks. The last instruction of a block is always a jump to the successor block. Hence, MIS program built up basic block graphs. The instructions on basic data types are that of the target machine.