A probe includes a first end and a second end, which are ends in an axial direction; and a first arm and a second arm having a columnar shape and arranged in parallel in a width direction perpendicular to the axial direction to form a first slit therebetween. The first arm and the second arm extend from the first end to the second end. The first and second arms are connected with each other with the first end and the second end as connection regions. In at least one of the first end or the second end, a second slit having an opening width in the width direction narrower than the first slit is formed in the connection regions in the axial direction to communicate with the first slit. Side surfaces of the second slit are formed in a tapered shape, viewed in a cross section along the width direction.