| Document And Entity Information | May 21, 2024 |
| Document Information [Line Items] | |
| Entity, Registrant Name | Firsthand Technology Value Fund, Inc. |
| Document, Type | 8-K |
| Document, Period End Date | May 21, 2024 |
| Entity, Incorporation, State or Country Code | MD |
| Entity, File Number | 814-00830 |
| Entity, Tax Identification Number | 27-3008946 |
| Entity, Address, Address Line One | 150 Almaden Blvd., Suite 1250 |
| Entity, Address, City or Town | San Jose |
| Entity, Address, State or Province | CA |
| Entity, Address, Postal Zip Code | 95113 |
| City Area Code | 800 |
| Local Phone Number | 976-8776 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common stock |
| Trading Symbol | SVVC |
| Entity, Emerging Growth Company | true |
| Entity, Ex Transition Period | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001495584 |
