Unless you have some proprietary hardware you're using, a standard PC ATX switch is a momentary on switch with a minimum of two leads. They can have more leads, the others are just unused. This is why some builders are able to use arcade buttons to replace their PC switch.
So the answer to your question is yes, you can use that. Just make sure you wire it appropriately. You likely have two pairs (the first and second row) that are grouped together focus only on the top or bottom row. The center should be your common while one is always "on" and the other is always "off". If you have a multimeter, you can easily figure it out. Otherwise, if the PC behaves strangely, swap the connection on the "left" (in the picture) to the connection on the "right".
Everything I said is for the ATX style switch. If you're trying to wire up the MAINS feeding the PSU or wiring up an AT style power supply just stop what you're doing right now and change your plans.