class C { C() {print("C()!!!"); } ~C() { print("~C..."); } C2@ c2; } class C2 {}; then in main(): C c(); it prints: C()!!! the deconstruction is never called! but when I define "c2" as "C2 c2" then it prints:C()!!! ~C... So what should I do to release object with handle member?

As objects with members as handles can potentially form circular references the garbage collector keeps track of these instances.

So, you'll need to call engine->GarbageCollect() at an appropriate time to free this instance. The GC in AngelScript is not invoked automatically, as the game developer will in general want complete control over when it is supposed to run.

Regards,
Andreas