Ad-Da'wa Mosque is a place for muslim people of SMAN 15 Surabaya to pray. Ad-Da'wa has some facilities. The facilities are religion lab, toilet, wdhu place, fingerprint, Al-Qur'an, and praying tool. Not only for praying, this mosque is also built for practice while studying religion, committee meeting, extracurricular, etc.

After dhuhur and ashar praying there are few students that chosen by SKI to tell short speech or commonly called"kultum". One of SMAN 15 Surabaya student, M. Ichwan Firmansyah said that the benefits that we will get from kultum are to train the students for public speaking and increase student knowledge about religion.

Not only activities that related to Moslem's commemoration days, SKI also hold an activity that called "SOFT". "SOFT" means Save Our Faith Together. One of comittee SKI M. Ashari said the purpose of this activity to train the students to discuss about islam religion.