IPhone 5 won't turn on?

I haven't used it in a couple of months, it worked fine last time i used it, I put it in the charger and it has the apple logo as if it was turning on, but after a couple of seconds it turns off, and does it again, what can I do?

Get a new phone

Cool

The battery's really drained after sitting all that while, and may or may not have suffered internal damage as a result. Leave it on the charger a while longer to see if it finally catches.