Hara, T. Fukami, K. Inagaki, T. Kinjo, R. Kondo, C. Otake, Y. Takebe, H. Tanaka, H. Togawa, K. TUA03 electron operation undulator kicker laser 2015 2015-12 A new undulator beamline (BL2) was installed in September 2014 at SACLA. Following the installation of this second beamline, a DC switching magnet was replaced by a kicker magnet and a DC septum magnet for bunch-to-bunch multi-beamline operation. The commissioning of the new beamline and bunch-to-bunch operation was started early this year. Since SACLA has been operated with much higher peak currents around 10 kA compared to its original design value of 3 kA, the CSR effect in the beam transport line to BL2, where the electron beam is deflected twice by 3 degree, turns out to be non-negligible. BL2 is currently operated with reduced peak currents and the photon pulse energies of 100-150 μJ are obtained with increased undulator K-values around 2.6-2.85. Although the photon pulse energies of BL2 are still smaller than those of the existing beamline (BL3), the expected stability of the electron beam orbit after the bunch-to-bunch BL switching was achieved and simultaneous lasing at the two beamlines was demonstrated with 8 GeV electron beams. We will report the status and operational issues related to the multi-beamline operation at SACLA.