Annual report pursuant to Section 13 and 15(d)

Document And Entity Information

Document And Entity Information - USD ($)
12 Months Ended
Sep. 30, 2019
Nov. 18, 2019
Mar. 31, 2019
Document And Entity Information      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Sep. 30, 2019    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Entity Registrant Name Arch Therapeutics, Inc.    
Entity Central Index Key 0001537561    
Current Fiscal Year End Date --09-30    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Non-accelerated Filer    
Entity Public Float     $ 58,000,000
Trading Symbol ARTH    
Entity Common Stock, Shares Outstanding   187,862,947  
Entity Shell Company false    
Entity Emerging Growth Company false    
Entity Small Business true    
Entity Interactive Data Current Yes