A non-aqueous electrolyte solution for secondary batteries, comprising a lithium salt and a liquid composition, wherein the liquid composition comprises a specific fluorinated solvent and a cyclic carboxylic acid ester compound, and may contain a specific compound, the content of the fluorinated solvent is from 40 to 80 mass %, NANLi is from 1. The IP telephony system includes an IP network; at least one gatekeeper connected to the IP network, having a DHCP server and a TFTP server; an IP phone connected to the gatekeeper for voice communication service; and an AAA server. With such composition of the scanning mirror unit, a reflecting member having a sufficient thickness can be employed for the movable mirror, by which a high power laser beam effective for treatment of affected parts, etc.