DIPAC2011 (European Workshop on Beam Diagnostics and Instrumentation for Particle Accelerators 2011) was held at Cap San Diego in Hamburg from 16/May to 18/May in 2011. The number of participants is about 290. We discussed various topics related with the beam diagnostics and instrumentation. After the workshop, many of the participants joined in the DESY tour. In this article, we report the overview of the workshop and the DESY tour as well as several topics presented in the workshop.