Proteases may include an amino acid sequence which has at least 70% sequence identity with the amino acid sequence given in SEQ ID NO:1 over its entire length and has (i) one or more first amino acid substitutions at positions corresponding to positions 3, 4, 99, 199, or combinations thereof, and (ii) one or more second amino acid substitutions at positions corresponding to positions 9, 21, 42, 44, 105, 112, 113, 131, 137, 139, 141, 145, 159, 168, 176, 177, 182, 193, 198, 204, 205, 206, 210, 212, 230, 234, 250, 253, 255, 259, 267, or combinations thereof based on the numbering according to SEQ ID NO:1, and relates to the preparation and use thereof. Proteases of this kind demonstrate very good stability with good cleaning performance.