KEK-MSL report 1999

This report consist of four kinds of categories: facility report, scientific activities, KEK-MSL - TRIUMF/RIKEN-RAL Collaboration and appendix. During this period, special C.O.E. budget was approved to construct axial-focussing large solid-angle surface μ+ channel at the No.2 laboratory, which may contribute a drastic upgrading of the muon beam production. In the facility report, status summary of KEK-MSL Activity, conceptual design of Dai-Omega superconducting surface-muon channel and a status of muon science in the joint project are reported. Scientific activities and KEK-MSL - TRIUMF/RIKEN-RAL Collaboration contained 34 and 7 papers, respectively. 40 Publication list(1999), beam time statistics FY 1999, list of proposal in FY 1999 etc., are indicated in appendix. (S.Y.)