1 of the embodiment fig1 a illustrates a plan view and fig1 b illustrates a side view the insertion apparatus 1 includes a nozzle body 10 that serves as an apparatus body which is formed with a cross section having a substantially rectangular tube shape so that one side is largely opened hereinafter the largely opened side is referred to as a trailing end 10 b and the other side end is provided with a nozzle portion 15 as a thinly narrowed insertion tube and an obliquely opened leading end 10 a and a plunger 30 which is inserted into the nozzle body 10 so as to move in a reciprocating manner furthermore in the description below the direction directed from the leading end 10 a of the nozzle body 10 toward the trailing end 10 b is set as the front to rear direction the direction perpendicular to the drawing paper of fig1 is set as the up to down direction and the direction perpendicular to the front to rear direction and the up to down direction is set as the left to right direction the vicinity of the trailing end 10 b of the nozzle body 10 is integrally provided with a hold portion 11 which projects in a plate shape and is used for a user to hold the hold portion by fingers when the plunger 30 is pressed toward.