It depends a lot on what your relationship with your manager is. A good manager will support you and if you explain your reasons for leaving will either try to

It depends a lot on what your relationship with your manager is. A good manager will support you and if you explain your reasons for leaving will either try to find a way to fix problems and provide you with those same upsides where you are; or if that's not possible (for instance, your reason is that you want "Facebook" on your resume), will be supportive and maintain the relationship because there's always the possibility your paths will cross again in the future. A mediocre or bad manager can be mediocre or bad in any number of ways, and any advice would be highly situational and specific. The only general piece of advice I can offer is to express appreciation for the opportunities you've been given and to make it clear that your reason for leaving is not something you blame your manager for.