The present invention relates to a surgical device. The surgical device may include: a needle device; an aspiration device, which is attached to or detached from the needle device, for tissue sampling; an injection device, which is attached to or detached from the needle device, for drug injection; and an electrode device, which is attached to or detached from the needle device, for thermal treatment. Therefore, any one of the aspiration device, the injection device, and the electrode device is attached to or detached from the needle device, thereby being capable of performing tissue sampling, drug injection, and thermal treatment. Thus, the time and costs required for tissue sampling, drug injection, and thermal treatment are reduced and foreign substances can be prevented from flowing into a surgical site in advance.