Inclusion Criteria:  Subjects of each gender aged 18 years or older at the time of informed consent. There is no upper limit of age. Subjects who have received oral and written study information, accepted participation and signed the informed consent document. Subjects who are willing and mentally and physically capable to understand and follow the treatment and follow-up schedule including post-treatment care instructions. Subjects who are willing to have photographs and images taken of the treated lesions to be used anonymously or coded in evaluations and publications. Subjects, who have histologically and clinically verified basal cell carcinoma either as newly diagnosed non-nodular cancer (one group) or as a recurrent cancer in a local site (another group) previously treated with any method practiced in dermatology clinics, hospital or the primary sector. Tumors of thickness more than 2.0 mm measured by ultrasound or OTC are considered of the "nodular" type. Thus, only tumors of thickness 2.0mm and less are included.  Exclusion Criteria:  Subjects who are less than 18 years at the time of informed consent. Subject is pregnant or lactating at time of first treatment Subjects with extensive, invasive or advanced skin cancer when another method in use such as radiotherapy or Mohs' surgery has priority and offers the patient better opportunity of cure. Cancers on anatomical sites where the ultrasound probe cannot be adapted for anatomical reasons Any systemic disease that according to investigator's assessment may interfere with the spontaneous course of a skin cancer. Any condition predisposing to treatment-related adverse effects or complications from the ultrasound treatment. Subjects with abnormal scar formation Subjects with impaired wound healing Subjects with the basal cell carcinoma under study located nearby (<5 cm) an implant or a site injected with a dermal filler or paraffin. Subjects with any other acute or chronic condition which, in the opinion of the investigator, could interfere with the conduct of the study.