There provided a 12-membered-ring macrolactam derivative having antitumor activity: A compound represented by Formula (1) or a salt thereof. In this Formula, R
1
is a hydrogen atom, a C
1-6
alkyl group, a C
1-6
alkylcarbonyl group or a C
6-14
arylcarbonyl group; R
2
is a hydrogen atom or a C
1-6
alkyl group; R
3
is a hydrogen atom or a hydroxyl group; R
4
is a hydrogen atom or a hydroxyl group; R
5
is a hydrogen atom or a C
1-6
alkyl group; R
6
is a hydrogen atom or a hydroxyl group; and R
7
is an acetyl group or the like.