1. No opportunities to grow. 2. As a vendor, which operates on the customer's site, this makes for unfavorable working conditions.
If you're an ambitious, hard worker, looking for a long term career, you will probably not be satisfied with this position after about 3 years. On the other hand, if your straight out of college, ASML is a foot in the door to an intriguing industry.
If you're the "less than ambitious type," this job is perfect for you, as it allows you to coast along for years with, little to no accountability.