How to replace this osb with better wood for laying laminate flooring?

[localsearch]

I have no experience with any DIY project. I am going to lay laminate flooring (10mm) with wood fiber underlay (5mm) on a subfloor which is a suspended floorboard. There is an osb there near the heater. (attached photos)
1) Can I just lay laminate flooring (10mm) on it without replacing it?
2) If I have to replace it. Where can I buy the wood floorboard as a replacement? Any advice on how to do it?

Many thanks.

 

[Why Not Indeed]

It doesn't look like OSB to me, but no matter what it's made of it needs to be solid, or at least as good as the surrounding floorboards. If it's weak then it won't support the laminate if it's stood on.