I readed the doc & example pages, and also the fasm.pdf. The doc mentioned invoke, stdcall, cinvoke, ccall, proc, endp. But I don't know how to balance the stack.

In masm I just define a subroutine and invoke it. The masm/macro balance the stack automatically.

In fasm I define a subroutine and stdcall it. The program crash. Do I have to manage ESP, EBP and RET <int> in my subroutine? I looked at the examples, their procedure just use RET, and don't need to take care ESP, EBP.

I am very confused. Can someone give a simple example to show me how to do it correctly, please?

Have you spelled RET as "ret" (i.e. all lowercase)? It is important because the proc macro defines the ret macro but not RET nor any other combination of lower and upper case.

Oh! I didn't know that ret is macro, while RET is mnemonic.
Problem solved.
Thank you very much!!

It is a macro under the proc context, otherwise it is also a mnemonic of the CPU instruction RET (endp macro purges ret macro). There is no case sensitivity for CPU instructions but macros are case sensitive.

By default, "ret" in any combination of lowcase/upcase case letters is mnemonic too, it is just aliast for "retn". But inside "proc", this instruction is overloaded by "ret" macro. Problem is, macro names in FASM are case sensitive, so only "ret" gets overloaded, and "RET", "Ret", "ReT" etc. all remain just aliases for "retn".