A lubricant supplying device includes: lubricant; a supplying member that supplies the lubricant to a lubricant supply target; and a remaining amount detecting unit that detects that a remaining amount of the lubricant is equal to or smaller than a certain amount. The remaining amount detecting unit includes a first electrode member and a second electrode member. The lubricant supplying device includes a member that causes at least a part of the second electrode member to move and causes the second electrode member to abut the first electrode member with an increase in consumption of the lubricant.