Hi,
After using the Low Level Format Tool to format my usb flash memory, the flash memory size has been reduced from 1GB to 60MB !!!!!!!

I have tried many ways and tools to restore the original capacity but with no use, the original size is not even shown in the unallocated, it is only showing 60MB as a whole!!!

How could I restore the original capacity, or view the hidden defect list ???!!!

Is it a Sandisk Cruzer or a Kingston?

You may have to use Diskpart to do it, as diskpart unmounts the disks before doing partitioning, and windows tools do not.
It is also possible the USB is now faulty, as I have seen this quite a few times.

Any special reason you are worried about fixing a 1GB USB?

i think as Haque an i think the best in this case is waste USB pen and repalce it

The problem is not replacing the usb flash drive, what I am asking about is that will every usb flash memory that I format with your low level tool have a 50%/50% chance of destroying and corrupting the flash memory?!!!

Witch LLF tool are you ussing?

You don't need to low level format your flash memory. I would highly suggest using a tool specifically for flash, either from your flash vendors website, or actually this tool which is excellent...
SD Formatter (it doesn't only do SD Cards..) https://www.sdcard.org/downloads/formatter_4/

The issue you had is probably not due to the tool but flash drive was faulty or just going faulty.

FWIW, not sure if it is an omission or it is not intended for USB Flash drives but this statement does not mention USB Flash drives: