I would take 3 steps:
-Get rid of their food sources. Clean the crap out of your apartment... pull the stove out, get behind the refrigerator, under kitchen cabinets, inside the kitchen cabinets, etc... and do the same for the other rooms.
-Find their access points and seal them off. You'll likely find some of these as you clean. Roaches can get in through tiny spaces like gaps between baseboard and floor, electrical wiring holes through drywall behind ovens, etc. Use caulk, foam, weatherstripping, whatever it takes.
-Put down some sort of roach traps. Locate them strategically and according to manufacturer's instructions/suggestions... being mindful of pets and children, if you have any.
Those three steps should solve your problem. Remember that putting chemicals down is not a first step and aside from roach traps, you probably don't need to spray at all unless your roach problem is severe. Any kind of pesticide control method is more of a back-up to the other two.