A guidewire suppresses an increase in operating resistance during pushing and pulling within a blood vessel that is extremely crooked and secures sufficient operability. The guidewire includes a core shaft and a coil body wound around the core shaft. The core shaft includes a first shaft portion positioned inside the coil body and a second shaft portion positioned proximally from the coil body. A twisted portion that is twisted along a longitudinal axis of the core shaft is provided in at least part of the second shaft portion.
