Most dogs want lots of attention, but Chihuahuas seem to need a lot more than many other breeds. Just how much attention and time does your Chihuahua really need? The answer is that your Chihuahua needs all the attention you can give him. As far as he is concerned "too much" does not exist. For many owners their Chihuahuas become like children.
Many owners spoil their Chihuahuas rotten, showering them with huge amounts of time and attention. This is fine and your Chihuahua will absorb it all. He will repay you with all the love and affection you can stand and then some. That said you must be careful. If something happens in your life that doesn't allow you to spend the time with your dog that he is used to, he will not understand and is liable to react as a result.
To avoid sulks and bad behaviour the best thing to do is to establish the time you can spend with each other. Make it part of your daily routine and stick to it. Dogs love routines. Make sure that during this "Chihuahua time" all your attention is focussed fully on your dog.
During the rest of the day you can go about your daily business. Allow your Chihuahua to follow you around the house and whenever possible take him with you if you have to go out. However do not take him every time you go out, otherwise when the time comes that he can't go with you he will not understand and there is no way that you will be able to explain that to him.
To recap, it is fine for you to spoil your Chihuahua provided that there aren't going to be any changes in your life that could affect the amount of attention you can give him later. If this is a possibility try not to spoil your Chihuahua too much or you will both suffer.